1. Too much water. Overwatering manifests itself through wilting and leaf fall - which makes it easy to confuse with underwatering. Besides, moist environments make it harder for oxygen to circulate but are perfect starting points for other diseases.
2. Too little water. Dry soil is a sure sign that your plant hasn't been able to get the nutrients flowing and engage in photosynthesis properly. Thus, leaves may start to droop and lose color.
3. Wrong amount of fertilizer. Good intentions may cause us to be generous with fertilizers. But the chemical nature of these substances burns the leaves and the roots if overapplied. Too little fertilizer is safer on the one hand; on the other, it will get you nowhere trying to deal with nutrient deficiency and slow growth.
4. Too high temperature. 75°F (24°C) is the warmth limit for most indoor plants because they can't match the humidity and sunlight accordingly to deal with the heat.
5. Too low temperature. Along with sudden temperature shifts, this is a bigger danger, which may lead to plant death. The temperatures should not drop below 50 - 55°F (10 - 13°C).
6. Poor moisture level. You might consider getting an air humidifier to attach around a heating or a ventilating system.
7. Too much sunlight. Excessive sunlight weakens the leaves' membranes, interrupting photosynthesis and growth processes.
8. Too little sunlight. Sun starvation makes plants more susceptible to diseases.